Tower of a wind power installation

ABSTRACT

There are various pylons of wind power installations, primarily lattice mast pylons, tubular steel pylons or concrete pylons. In the case of pylons of concrete, there are various possible ways of producing same, inter alia also erecting pylons from ready-made reinforced concrete parts, wherein the individual ready-made reinforced concrete parts form respective segments which are laid one upon the other and which are then braced to each other._The object of the invention is to speed up construction of a pylon comprising segments disposed in mutually superposed relationship, with a bonding material between the segments._A pylon of a wind power installation, wherein the pylon comprises mutually superposed segments and there is a bonding material between the mutually superposed segments, and a heating element is provided in the upper region of the downwardly disposed segment and/or in the lower region of the upwardly disposed segment on the side of the segment, which is towards the oppositely disposed segment.

FIELD OF THE INVENTION

This invention relates to a method of assembling a pylon for a windpower installation, and more particularly, to a structure and method forconnecting two segments of a pylon to each other.

BACKGROUND OF THE INVENTION

There are various pylons of wind power installations, primarily latticemast pylons, tubular steel pylons or concrete pylons. In the case ofpylons of concrete, there are various possible ways of producing same,inter alia also erecting pylons from ready-made reinforced concreteparts, wherein the individual ready-made reinforced concrete parts formrespective segments which are laid one upon the other and which are thenbraced to each other. A process for producing a pylon from ready-madereinforced concrete parts is known for example from DE 100 33 845.3.

In the case of such pylons of concrete segments, the individual segments(in practice each segment is of a different shape) are not only simplylaid one upon the other, but they are also connected to each other byway of a suitable bonding material. Those bonding materials can be apolymer (for example epoxy resin) and the layer thickness of the bondingmaterial is usually at least 2 mm.

When now such a segment-type pylon is produced, the procedure, afterpositioning a segment, involves applying to the top side of the segmentthe bonding material which then in turn can harden after the nextsegment has been laid in place. That in turn is followed by applicationof bonding material to the freshly laid segment, and so forth.

Under some circumstances however a problem can arise with the bondingmaterial when the pylon is erected at a cold time of the year. Morespecifically, the bonding material usually requires a minimumtemperature for it to harden and, if the outside temperature is low, forexample around 0° C., either the bonding material does not harden orhardening takes a very long period of time, which considerably delaystotal erection of the pylon.

BRIEF SUMMARY OF THE INVENTION

One object of the invention is to speed up construction of a pyloncomprising segments disposed in mutually superposed relationship, with abonding material between the segments.

In accordance with the invention that object is attained by the featuresof claim 1. Advantageous developments are set forth in the appendantclaims.

In accordance with the invention, at least one side of segments whichare disposed in mutually superposed relationship is provided with aheating module and said heating module preferably comprises a simpleheating wire, a PCT resistance wire or also steel wire, such as weldingwire.

If a high current, for example in the range of 70 to 150 A, flowsthrough such a wire, then the wire heats up and the bonding materialapplied to the top side of the segment can harden quickly in the desiredmanner, in spite of cold outside temperatures.

To achieve a good heating effect, it is advantageous if the heatingmodule is provided over the entire surface area within the upper regionof a concrete segment in order to achieve maximum possible transmissionof heat to the bonding material.

That great heating effect can also be achieved for example if a heatingwire is arranged in a meander configuration within the upper region inthe concrete of the pylon segment and, of that heating wire, then onlythe two connecting terminals are still accessible. It is then possibleto connect to those connecting terminals for example a conventionalwelding transformer which is capable of passing a high current throughwire, so that then the desired heating effect in relation to the upperregion of the segment and therewith also the bonding material occurs.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The invention is illustrated hereinafter with reference to the drawingin which:

FIG. 1 shows a top plan view on to a pylon segment according to theinvention,

FIG. 2 shows a measurement curve in respect of various measurementpoints and the ambient air of a pylon segment according to theinvention,

FIG. 3 shows an illustration of the manner of laying a heating wire inthe pylon segment when segments are disposed in mutually superposedrelationship, and

FIG. 4 shows a view of a pylon, consisting of pylon segments, of a windpower installation.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a round pylon segment 4, viewing from above with a cut-awaycross-section at line c-c removed from the surface of a pylon segment.It is to be seen in this respect that a heating module 1 is positionedin the upper region 2 of the pylon segment, the heating modulecomprising a heating wire 5 which is disposed in a meander configurationwithin the concrete segment 4, as shown. It is also possible to see twoconnecting terminals 6 a, 6 b for the heating wire 5, to which it ispossible to connect for example a welding transformer which generates ahigh current which can be passed through the heating wire 5 so that theheating wire 5 is heated and then also provides for heating the concretein the uppermost region of the segment so that the bonding material onthe segment can harden.

FIG. 4 shows a completed pylon 10 being composed of a plurality ofsegments labeled generally S. Some of the segments are labeled tospecific reference numbers, such as segments 2, 4, 6, 10, etc. A groupof the segments are prefabricated and stacked on top of each other in asuperimposed relationship as shown in FIG. 4 in order to construct acomplete pylon 10 which as a wind power installation at the top thereoffor the generation of electrical power from wind energy.

FIG. 3 shows an illustration of segments which are laid in mutuallysuperposed relationship. Illustrated here are two segments 4, 6 whichare arranged in mutually superposed relationship and of which the lowersegment 4 is shown in a cut-away cross-section at line c in the regionof a reinforced concrete arrangement (which is not of particularsignificance here). It is also possible to see there the heating wire 5which is laid in the upper region of the pylon segment. The segments 4and 6 are arranged in mutually superposed relationship in such a waythat casing tubes 7 of a tensioning device in the segments 4, 6 aredisposed in substantially aligned mutually opposite relationship. Thetensioning device 8 is let into the lower segment 4 in positivelylocking relationship and the upper edge of the peripherally extendingrim terminates flush with the surface of the segment 4. The tubularportion 12 engages into the casing tube 7 which is integrated in thesegment 4.

A seal 20 is fitted in the part of the device 8, which is provided toreceive the seal 20, and the seal bears with its top side firmly againstthe lower segment 6.

When erecting the pylon comprising the segments 4, 6, firstly preferablythree spacers and shims 32 are arranged distributed at approximatelyequal spacings around the periphery on the upwardly facing surfaces ofthe segment 4 which was fitted last, being the lower segment.

The spacers 32 are preferably of wood and are of a height of about 5 mm(depending on the surface roughness of the segments), which correspondsto the intended spacing 30 between the segments 4, 6 after assembly. Themodulus of elasticity of wood is in a range which on the one hand makesit possible for wood to be able to withstand for some time the forceswhich occur in the pylon, but which on the other hand provides thatirregularities and unevenness in the mutually opposite surfaces of thesegments 4, 6 are pressed into the wood and thus flaking-off orchipping-off phenomena on the segments 4, 6 are avoided.

In that respect, the spacers 32 act as shims so that leveling of thesegments 4, 6 can be achieved by suitable selection of the height of thespacers 32 (the spacing may also be approximately only 2 mm), inaccordance with the inevitable production inaccuracies of the segments4, 6.

Before the operation of laying the upper segment 6 and the lower segment4, a bonding material 34 is applied to the upper surface of the segment4 to cover the area thereof. In that respect the positions at which thecasing tubes 7, 8 in the segments 4, 6 and the casing tube 7 in theupper segment 6 and the device 8 with the seal 20 in the lower segment 4are in mutually opposite relationship are left clear upon applying thebonding material 34, insofar as the bonding material 34 can be appliedas far as the projection 23.

The bonding material 34 which is applied to cover the surface area ispreferably an epoxy resin (or another polymer) and is applied at leastin a layer thickness of about 2 to 6 mm which substantially correspondsto the intended spacing 30 between the segments 4 and 6.

When such a pylon is constructed at the cold time of year, where thetemperature is not infrequently below the freezing point for the entireday (also because wind power installations are also erected at veryunprotected positions), the epoxy resin normally hardens, if at all,only very slowly, which overall greatly slows down the procedureinvolved in erecting the pylon, because further positioning of furthersegments also presupposes hardening of the epoxy resin between the lowersegments which have already been positioned.

In the case of the pylon according to the invention the pylonconstruction team can then activate the heating modules or heating meansalready provided in the segments, by for example a welding transformerbeing connected to the heating wire by way of the connecting terminals 6a, 6 b. The welding current is in a range of 60 to 150 A (or below thator above it). The segment 4 now heats up at its top side, and thebonding material also, and the bonding material can harden as desiredwithin a short time.

As the provision of a heating module in the form of a normal steel wireor heating wire or welding wire is very convenient and inexpensive, itcan remain in the concrete of the segment even after the pylon hashardened. In any case a pylon segment includes a plurality of steelbracings in order to increase its strength.

In order to avoid the heating wire 5 coming into contact with otherelectrically conducting parts in the segment, it may also be appropriateif the heating wire 5 is provided with a heat-conducting butelectrically insulating layer. Such insulation however should beresistant in respect of shape and heat at temperatures of up to 60 to100° C.

FIG. 2 shows the temperature characteristic of an embodiment of theinvention. The temperature measurement starts in this graph atapproximately 1900, which corresponds to 7:00 p.m. The 7:00 p.m. time isat approximately time T1 as shown on the graph. The temperature plotshows the ambient temperature, as well as the concrete and heating linetemperatures as time continues. At time T1, the outside ambienttemperature gradually drops below −5° C. At time T2, the concrete aswell as the heating line also begins to fall in temperature towards alow temperature following the temperature drop of the ambient air whichoccurs at approximately 2200 (namely 10:00 p.m.). It can be seen in thisrespect how the outside temperature curve firstly drops to a range ofabout −12 to −15° C.

Above the temperature curve there are the curves K1, K2 and K3, whereinK1 is the temperature of the heating line (heating module, heatingwire), K2 is the temperature in a concrete corner and K3 is thetemperature at the concrete center (surface of the segment). It can beseen that at the time T3 the heating current is applied into the heatingline 5. This is applied to terminals 6A and 6B in order to cause theheating wire 5 to increase in temperature. As can be seen, as soon as acurrent of about 80 to 90 A flows through the heating wire 5, thetemperature rises almost linearly and the temperature of the concretealso rises with the temperature of the heating wire, delayed by a shorttime. In that way the bonding material, in the specific case thereforethe epoxy resin, can rapidly harden and the operation of laying downfurther segments can progress quickly. Thus, even though the ambient airremains cold and even until past noon the next day, time T4 is still at−10° C. The temperature of the concrete has been caused to rise by theheating wire so that the temperature tracks that of the heating wire.The appropriate temperature can therefore be selected in order to causethe epoxy resin to be hardened and cured even though the ambient airremains cold.

It will be appreciated that it is also possible for the heating wire tobe provided not only in the uppermost region of the lower segment but inaddition also in the lower region of the upper segment 6 so that stillmore heat can be applied to the bonding material, which furtheraccelerates hardening thereof.

The variant according to the invention, for heating a segment, has theadvantage that it is highly favorable, and finally the costs of thenormal steel wire which is used as the heating wire are in the region ofa few hundredths of a German mark per meter.

The operation of laying such a heating wire is also very uncomplicatedand can be quickly finished in production of the segment.

Therefore, there is also no disadvantage if the heating wire remains inthe segment itself, even if the heating wire is not used at all becausethe pylon is erected in warm temperatures.

When the heating wire is provided however it is also possible to erectthe pylons of wind power installations even at the cold time of the yearand thus irrespective of the weather and the season.

It will be appreciated that the heating wire may be laid not only forexample in a meander configuration but in any other form, even in such away that the heating wire itself assumes the shape of a circle.

FIG. 4 shows a view of a pylon 10 comprising pylon segments, thesegments being labeled 2, 4, 6, 8, etc. according to the invention whichare placed one upon the other and which are braced relative to eachother by means of a bracing device (not shown).

All of the above U.S. patents, U.S. patent application publications,U.S. patent applications, foreign patents, foreign patent applicationsand non-patent publications referred to in this specification and/orlisted in the Application Data Sheet, are incorporated herein byreference, in their entirety.

From the foregoing it will be appreciated that, although specificembodiments of the invention have been described herein for purposes ofillustration, various modifications may be made without deviating fromthe spirit and scope of the invention. Accordingly, the invention is notlimited except as by the appended claims.

1. A pylon of a wind power installation, wherein the pylon comprises:mutually superposed segments; a bonding material between the mutuallysuperposed segments; a heating element positioned in the upper region ofthe downwardly disposed segment and/or in the lower region of theupwardly disposed segment on the side of the segment, which is towardsthe oppositely disposed segment.
 2. A pylon according to claim 1characterized in that the heating element comprises a heating wire or aPTC resistance wire which is arranged on the top side of the segment orbelow the top side in the segment itself.
 3. A pylon according to claim2 characterized in that the heating wire or the PTC resistance wire is awire through which current flows for heating thereof.
 4. A pylonaccording to claim 1 characterized in that the heating wire is laid in ameander configuration at the top side of the segment or in the lowerregion within the segment.
 5. A pylon according to claim 1 characterizedin that to heat the heating wire there is a current connecting terminalto which for example a welding transformer or another current-generatingdevice can be connected.
 6. A wind power installation comprising a pylonaccording to claim 1.